Kevin, According to Brock & Hasenpusch in 'The complete field guide to stick and leaf insects of Australia' (CSIRO Publishing, 2009), males have a subgenital plate in the form of a characteristic 'bump' underneath the end of the abdomen, whereas females have in the same position an operculum which is 'boat-like' and 'often fairly flat'. Males are usually smaller than females and often much more slender. In winged species - such as your Didymuria violescens (if I have the name right) - males can often fly quite well, while females may have shortened wings that, at most, may break a fall.